Manufacture of geass



v No Drawing. I,

STATES PATENT OFFICE.

-nUen-;A. em, or summon, onto. 4

manurkcronnor crass.

To all whom it may concern:

Be it known that I, HUGH A. GALT, citizen of the United States, residing at Barberor finely divided form, vbecause the water "f absorbed thereby makes the massmushy or ton, in the county of Summit and State of Ohio, have invented certain new and useful' Improvements in the Manufacture of Glass, of which the following is a Specification.

This invention relates to the manufacture of glass, and has for its principal ohiec'ts the provision of a glass batch which cheaper and in some respects more satisfaca tory than :those now employed, and which? will permit-the use of niter cake, cylinder cake or other similar substances in place of certain of the more expensive substances now in use. l

Niter cake, a biproduct in the manufactureof nitric acid from sodium nitrate, and

cylinder cake, a biproduct in themanufac blocks and interferes with the melting and handling operations, and which also produces ascum whichv impairs the clarity and quality of the glass. Moreover the acid or bisulfate portion 'of the niter cake attacks the pots or tank blocks, and its fumes attack the exposed metal and other substances in the workroom. A ain, niter cake has not heretofore been used cause it .has not been feasible to store it inreserve in pulverized even liquid and therefore difiicglt' to handle, wh11e its strong acid efiect is-also likely to produce solution of nails inthe bin or other foreign substances which ix 'npair the quality of the glass.- o v Y,

The present invention I toward the proper utilization of niter cake, c .linder" 'cake' or the l ke in "a glass "batch,- an there-1. fore 'auns to put to use substances. which" have heretofore, been considered: of little or Specification of Letters Patent.

ramme A g. 12, 1919.

Application'filed December 15, 191 7. Serial No. 207,289.

low value or tosubstitute thesame for more -costly materials; 7

. The niter cake (and by this term hereinafter I mean to include cylinder cake and similar substances containing sodium bisulfate) may be utilized in a glass batch. in 'various'ways, a number of which will be referred to more in detail.

For. the purpose of comparison of the various new batches with the present'practice the following typical ordinary soda ash mix may be used as a basis;

Ty ical (Formula 1). 'Sand 1000' parts Soda ash (Na CO 298 parts Salt cake (Na SO 60-parts Salt (NaCl) 25 parts Limestone (GaCO 309- parts Goal (0) 3 parts Arsenic (A5 0 5 parts One ofthe new batches constitutes departurefrom the foregoing -only in the substitution of a mixture of niter cake and soda ash (or an equivalent for soda ash) for the I .60 parts of salt cake in the above-batch. The new batch in) tabulated form is as follows:

' Formula H. v

Sand 1000 parts Soda ash- 298 parts Mixtgrg:

o a as 16 parts 1 Niter cake-50 parts} u 6 parts Salt; 25 parts Limestone 309 parts Coal '3 parts Arsenic- 5 parts The mixture in this batch i5 preferably made up of 50 parts of niter cake and just.

sufficient soda ashto neutralize the free acid orthe acid effect of the niter cake, and may, or example, be ap roximatel 16 parts. If bicarbonate of so a, NaHC is .used in place of soda ash (and it will serve equally as well) approximately 1 times as much is required as the amount of sodaash; The

quantity of'soda ash or bica'rbonate is of.

course readily calculated chemically when the acid value of the nlter cake is know i turemay be ground to a relatively fine cond tion and mixed toget as a homogeneous particular -,-batch of 4 The two substances" forming the ,"-mix- I mass which is used in the mix as an entity,

case the resulting compound is substantially salt cake, or, more accurately, the effect is as though salt cake has been introduced into the batch, although the mixture has permitted the use of niter cake never before so used. The reaction between the niter cake and soda ash or bicarbonate, as the case may be, probably does not occur until a state of fusion is reached. Nevertheless neutralization of the niter cake in this manner disposes of its free acid or acid effect, prevents corrosion of the pots or surrounding metal objects, and avolds any possibility of the harmful effects of salt water. Grinding of the materials is not essential as the niter cake, for example, may be in lump form when separately introduced into the batch, as above stated.

Under normal conditions the foregoing substitution of the mixture for the salt cake involves a considerable saving in cost, a saving which is the greater under the present abnormal war conditions which have caused salt cake to rise in cost from $10.00 to $12.00 a ton in 1913 to $25.00 to $30.00 a ton today. A further advantage is due to the fact that the salt cake equivalent or substitute produced by the mixture of niter cake and soda ash or bicarbonate is very much purer than commercial salt cake, as a consequence of which the quality and Value of the glass are enhanced.

As an alternative, another mixture consisting of niter cake and limestone may be employed, the limestone serving'in this case to neutralize the acid effect of the niter cake and also furnish gypsum or calcium sulphate when the latter is either useful or harmless in the batch. This is a cheaper mixture than the first, due to the relatively lower cost of the limestone. On'the other hand, such a mixture may require to be roasted before adding to the batch to avoid early fusion of the niter cake and production of salt water before reaction with the limestone occurs. Still another mixture employs lime, either slaked, (laO H or unslaked, CaO, as a neutralizing agent for the acid effect of the niter cake. Such material would probably not require preliminary roasting before adding to the batch. All of these lime bases are of course added in amounts calculated to be approximately sufiicient to neutralize the acid efiect of the particular niter cake at hand. one such mix, utilizing ground limestone (preliminarily roasted with the niter cake) as the neutralizing base is as follows:

Formula Ill.

Sand 1000 parts Mixture:

siz calcined 708 parts Limestone 181 parts Coal 45 parts Another mix employing slaked lime is as Formulae III and IV may be used at exceedingly low cost because of the cheapness of the niter cake and lime as compared with the soda ash and salt cake ofthe typical mix, Formula I. 1

It will of course be understood that the foregoing formulae indicating a part of the possible modifications of the invention are merely illustrative and that the materials employed and the proportions thereof are capable of wide variation.

What I claim is V 1; The process of making glass Which consists in mechanically mixing together finely divided niter cake and a neutralizing base, adding such mixture to a lime silica batch, and fusing.

2. The process of making glass which consists in formin a mechanical mixture of finely divided nlter cake and a base in sufficient quantity to neutralize the acid effect of the niter cake, adding such mixture to a lime silica batch, and fusing.

-3. The process of making glass, which consists in forming a mechanical mixture of finely divided niter cake and a calcium compound as a neutralizing reagent, adding such mixture to a lime silicia batch, and fusing.

- 4. The process. of making glass which 

